@Jenner9 - Greetings from Canada. I travel with a carry on for all my cruises (have done ones up to a month long). Like others, rewear, do spot clean ups if I dribble, do sniff test 😝, etc. I'm used to living in cramped corners on a 30' sailboat, so limited to storage space, so the cabins on the cruise ships I go onto, is like living in a chateau (and I don't have to make up my bed or scrub the deck down). One tips, silk or bamboo undies are the way to go. They are anti-fungal, wash up fast and dry fast. For a month a way, I bring 3 pairs, wearing one. I find the less I bring, the less stress. I mean, most people will only see you once or twice, and I highly doubt they'll notice if you're rewearing something and if they do ... who cares!
As others have stated here too, how do you dress at home? I've been wearing the same leggings for the past week, crotch sniff, they're still okay. That's me though, a semi-minimalist who would rather save her back/arms from lugging heavy luggage.